Dimpled press stock



A ril 29, 1969 J. A. BREMER DIMPLED PRESS STOCK Filed March 14, 1967JAMES A. BREMER INVENTOR.

ATTORNEYS United States Patent 015cc 3,440,988 Patented Apr. 29, 1969U.S. Cl. 113-120 4 Claims ABSTRACT OF THE DISCLOSURE This inventionteaches the incorporation of non-nesting deformations into a normallynesting sheet metal object to enable such objects to be stacked andunstacked with ease manually or dependably by automatic machinery.

Background of the invention Sheet metal objects are routinelymanufactured by stamping in suitable dies. Such a stamping procedureoften involves the preparation and stacking of identical sheets of metalas blanks or the stacking of essentially duplicate parts during someportion of the manufacturing procedure.

Difficulty has been encountered in the past from the tendency of stackedsheet metal blanks or stacked and nested stamped parts to tenaciouslycling together and resist separation for subsequent processingparticularly if the parts are prepared from oiled stock. This difficultyhas resulted in the necessity for the use of more man power in theattendant sheet separation or in rendering automatic machinery for suchstamping processes more expensive and more unreliable than with thecurrent process.

Description of the invention The difficulties outlined above may beavoided by properly deforming the sheet metal blanks at any suitablestep in the manufacturing process. Stamping processes of this natureusually start with the preparation of sheet metal blanks from a metalreservoir normally a coil of sheet metal. Immediately after the blankshave been severed in sequence from the coil, each individual blankshould be worked to impart to it at least one local and non-structuraldeformation. The non-structural deformations in these sheet metal blanksshould be located so that it is impossible for such a sheet metal blankto nest with either the sheet metal blank immediately preceding orimmediately following such blank.

This invention is easily visualized by a study of the drawing whichdepicts a pair of stampings which are intended to serve as a portion ofan automotive gasoline tank. These two stampings are identical exceptfor the location of the non-structural deformations or dimples. Notethat dimples A and B in the lower stamping are located differently fromdimples C and D in the upper stamping. It is obvious that these twostampings may be partially but not completely nested and that when sopartially nested they may readily be separated for further processing.This separation may be done either manually or by machine.

It is clear that the dimples or non-structural deformations may be addedto the stamping at any convenient point in the process. For example,this dimpling may be done as a portion of the process for thepreparation of the blanks or may be done as a part of the stamping ordrawing process by which the stampings are fabricated.

It is clear that the non-structural deformations or dimples must belocated so that they do not interfere with the utility of the finalproduct or where they may be trimmed away from the final product.

An obvious variation of the process shown above is to modify thestructure shown in the drawing so that dimples A and B are coincidentwith dimples C and D but of different outline so that nesting is againimpossible. This structure is shown in the dotted dimples in the upperportion of the drawing with the outline of the dimples D and C modifiedso that nesting with dimples A and B is impossible even though the twosets of dimples are in the same location.

I claim as my invention:

1. The process of producing stampings from flat sheet metal comprisingpreparing in sequence a plurality of fiat sheets of metal of suitablesize to be deformed into a stamping, and locally imparting anon-structural deformation to different locations in each of the sheetsof metal so produced, these non-structural deformations being located ineach individual sheet so that it cannot nest tightly with either theimmediately preceding or the immediately following sheet.

2. The process recited in claim 1 in which the nonstructuraldeformations are imparted to the sheets of metal as an adjunct to thepreparation of the sheets of metal from a metal reservoir.

3. The process recited in claim 1 in which the nonstructuraldeformations are imparted to the sheets of metal as a portion of thestamping process.

4. The process of producing stampings from flat sheet metal comprisingpreparing in sequence a plurality of flat sheets of metal of suitablesize to be deformed into a stamping, and locally imparting anon-structural deformation to different locations in each of the sheetsof metal so produced, these non-structural deformations being arrangedin each individual sheet so that it cannot nest tightly with either theimmediately preceding or the immediately following sheet.

References Cited FOREIGN PATENTS 212,767 1/ 1961 Austria. 604,593 9/1960 Canada.

RONALD D. GREFE, Primary Examiner.

U.S. Cl. X.R. 22097

